In this work, we present a lower bound on the quantum Fisher information (QFI) which is efficiently computable near-term devices. This itself of interest, as show that it satisfies canonical criteria QFI measure. Specifically, essentially measure for subnormalized states, and hence generalizes standard in sense. Our employs generalized fidelity applied to truncated state, constructed via $m$ la...

Many real-world tasks include some kind of parameter estimation, i.e., determination a encoded in probability distribution. Often, such distributions arise from stochastic processes. For stationary process with temporal correlations, the random variables that constitute it are identically distributed but not independent. This is case, for instance, quantum continuous measurements. In this paper...

The natural gradient method has an ideal dynamic behavior which resolves the slow learning speed of the standard gradient descent method caused by plateaus. However, it is required to calculate the Fisher information matrix and its inverse, which makes the implementation of the natural gradient almost impossible. To solve this problem, a preliminary study has been proposed concerning an adaptiv...